The general goals of this program are to study a) the mutation of renal function in normally developing subjects, b) the relationship between developmental renal physiology and disease processes, and c) the natural history and optimal therapy of kidney disease in children. The animal experiments are conducted in an effort to determine the relationship between the renin-angiotensin-aldosterone system, the intrarenal distribution of blood flow and the development of acute renal failure; the roles of prostaglandins and the renin-angiotensin-aldosterone system in the maintenance of sodium homeostasis; the mechanism of the positive sodium balance prevailing during growth; the effect of hypoxia and acidosis upon renal function in the newborn; and the morphologic relationship between glomerular and tubular size during maturation. Clinical surveys include the determination of: 1) normal plasma creatinine concentration and its use for estimating glomerular filtration rate in both normal children and those with reduced muscle mass; 2) the normal plasma total CO2 content and its possible alteration in the syndrome of "late metabolic acidosis"; 3) the mechanisms responsible for delayed sexual maturation in children with chronic renal insufficiency; and 4) the effect of a summer camp recreational experience on the self image and peer relationships of children on chronic hemodialysis therapy. BIBLIOGRAPHIC REFERENCES: Haycock, G.B., Schwartz, G.J., Edelmann, C.M., Jr. and Spitzer, A.: Plasma creatinine (Pcr) and its use in estimating glomerular filtration rate (GFR) in children. Ped. Res. 10:439, 1976. Haycock, G.B., Schwartz, G.J., Edlemann, C.M., Jr. and Spitzer, A.: The Late Metabolic Acidosis (LMA) of Low Birth Weight (LBW) infants: Fact or Fiction? Ped. Res. 10:410, 1976.